javascript - 反应:在提交上获取数据,而不是在 onChange 上
问题描述
我让这段代码按我想要的方式工作。但是,它会在每次击键后获取和显示数据。当我点击提交时,我只希望它获取一次。
另外,如果我正在做的任何事情不是“最佳实践”,请告诉我,这样我以后就不会犯愚蠢的错误。
import React, { useEffect, useState } from "react";
export default function App() {
const [data, setData] = useState(null);
const [query, setQuery] = useState("");
useEffect(() => {
if (!query) return;
async function fetchData() {
const response = await fetch(
`https://www.omdbapi.com/?apikey=2e8b5857&s=${query}`
);
const data = await response.json();
const results = data.Search;
setData(results);
}
fetchData();
}, [query]);
const handleSubmit = (e) => {
e.preventDefault();
setQuery(query);
};
return (
<div
style={{
margin: 20,
}}
>
<form onSubmit={handleSubmit}>
<br />
<label>
Input Movie:{" "}
<input
type="text"
placeholder="ex. Harry Potter"
value={query}
onChange={(e) => {
setQuery(e.target.value);
}}
/>
</label>
<input type="submit" value="Submit" onClick={() => setQuery} />
</form>
{data &&
data.map((movie) => (
<div key={movie.imdbID}>
<h1>{movie.Title}</h1>
<h4>
{movie.Year} | {movie.imdbID}
</h4>
<img alt={movie.imdbID} src={`${movie.Poster}`} />
</div>
))}
</div>
);
}
解决方案
由于您只想要它之后submit
,您可以跳过useEffect
with[query]
并在您的handleSubmit
like 中复制相同的逻辑:-
import React, { useEffect, useState } from "react";
export default function App() {
const [data, setData] = useState(null);
const [query, setQuery] = useState("");
const handleSubmit = (e) => {
e.preventDefault();
if (!query) return;
async function fetchData() {
const response = await fetch(
`https://www.omdbapi.com/?apikey=2e8b5857&s=${query}`
);
const data = await response.json();
const results = data.Search;
setData(results);
}
fetchData();
};
return (
<div
style={{
margin: 20,
}}
>
<form onSubmit={handleSubmit}>
<br />
<label>
Input Movie:{" "}
<input
type="text"
placeholder="ex. Harry Potter"
value={query}
onChange={(e) => {
setQuery(e.target.value);
}}
/>
</label>
<input type="submit" value="Submit"/>
</form>
{data &&
data.map((movie) => (
<div key={movie.imdbID}>
<h1>{movie.Title}</h1>
<h4>
{movie.Year} | {movie.imdbID}
</h4>
<img alt={movie.imdbID} src={`${movie.Poster}`} />
</div>
))}
</div>
);
}
这是代码框:-